Processing of photographic film

ABSTRACT

Described herein is a portable film processing arrangement which is housed in a case-like receptacle comprising a base portion and a lid portion. Base portion 10 houses a plurality of processing units 30 which accommodate spiral holders onto which film to be processed can be wound automatically. Lid portion 14 houses a plurality of containers 18,19,20 which contain processing chemicals for processing the film. The chemicals are fed to the processing units 30 from the containers 18,19,20 as required by valves which are controlled by an on-board computer in a control section 45 located in the base portion 10 between the processing units 30.

BACKGROUND OF THE INVENTION

This invention relates to the processing of photographic film. Theinvention particularly relates to a processing unit for processingphotographic film which is portable.

There are several different ways in which the processing of photographicfilm can be achieved. A common way is to send the film to a processinglaboratory where typically it will be processed in a large processingunit. On a smaller scale a photographic film can be wound on to elementssuch as spiral reels and processed in a small light tight tank. Thechemicals used in the processing have to be mixed, raised to the correcttemperature and the whole process operated with a timer and thermometer.

Also small processors are available, but again these need the chemicalsto be mixed and they require connection to a water supply and have to beoperated in a dark room for the loading of a film. Usually they alsorequire a mains type electrical supply.

In a typical portable machine each film for processing is loaded onto aspiral in the dark usually in a dark room. Chemicals are supplied to themachine from external containers and typically the chemicals will besupplied as concentrates which are diluted to the correct concentration.As a rinse is used after every stage to overcome contamination themachines require connection to a water supply. This can make the processtime consuming and large volumes of effluent have to be discharged.Finally the film requires removal for a drying step.

SUMMARY OF THE INVENTION

The present invention is concerned with a portable processing unit whichattempts to alleviate some of these disadvantages.

According to the present invention there is provided a film processingunit comprising means for receiving a cassette containing undevelopedfilm, means for removing said film from said cassette and winding saidfilm onto a spiral type holder located in a processing chamber, saidloading means, said removal means and said processing chamber beinghoused in light tight conditions, receptacle means for containingprocessing fluid, means coupling the receptacle means to the processingchamber, valve means for selectively permitting flow of processingfluids between said receptacle means and said processing chamber, thearrangement being such that processing fluids can be dispensed from saidreceptacle to said processing chamber to perform a processing operationon said film and after said operation said fluid can be returned to itsrespective receptacle means or otherwise discharged.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described now by way of example only, withparticular reference to the accompanying drawings. In the drawings:

FIG. 1 is a perspective view of a portable processing unit in accordancewith the present invention, and

FIG. 2 is a sectional view of the processing unit.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings the processing unit is in the form of a caselike container having a base section (10) and a lid section (14)connected to the base by hinges (15). The base section (10) and the lidsection (14) each define volumes within which are located elements whichmake up a self-contained photographic film processing unit. The caseincludes catches (16) for securing the lid to the base and a handle (17)for carrying the case.

The lid section (14) houses three containers (18, 19, 20) each providedto accommodate chemicals used in the developing process. Each container(18) can include a heating element (22) which when energised acts toheat the solution contained in it to a desired temperature. Also eachcontainer is connected at its lower end to a conduit (23) which extendsfrom the lid section to a pump (24) disposed in the base section. Thepump is coupled by a first valve (25) and a three-way valve (26) to aprocessing unit (30). As can be seen in FIG. 1 of the drawings four suchprocessing units are located in the base section. The processing units(30) are arranged in spaced apart pairs, one adjacent each side wall ofthe base section.

Each processing unit (30) is defined by a light tight container having alid (31). The container defines a chamber (35) in which is located aspiral type reel (32) which can be mounted so as to be rotatable aboutits axis. The case can include drive means for rotating the spiral (32)about its axis. The container (30) also defines a smaller chamber (33)within which can be disposed a cassette (34) containing film to bedeveloped. Film extends from the cassette (34) to the spiral (32) by wayof a loading shute (37). The loading shute (37) is designed to bow thefilm slightly as it is fed to the spiral (32) thereby facilitatingpassage of the film between and into the side walls of the spiral. Theend of the film is connected to the spiral by clipping it to a belt(38).

Associated with each unit (30) is a manually operable knife (40) whichcan be used to cut the end of a film after it has been wound onto thespiral (32). A recess (41) is provided in the lid (31) above the knife.The cutting edge of the knife when it is moved upwardly can enter therecess (41) thereby facilitating the cutting operation.

Disposed between the spaced apart pairs of processing units (30) is acontrol section (45). This control section includes a microcomputer andassociated memory. Instructions and data can be fed into themicrocomputer by way of keys (48) and a display (49) is also provided.This can be a liquid crystal type display.

The computer is programmed to control developing process. It can outputsignals for controlling the valves (25, 26) and the pump (24) and alsoto control the heating of the chemicals in the containers (18, 19, and20). The computer can also receive inputs from various sensors providedin the processing unit which can sense for example when the latchinglevers of the lid have been closed or when the drive to the spirals.

In use the unit is operated with lid (14) open. Appropriate chemicalsare placed in the containers (18, 19, and 20) and are supplied in a formwhich requires no further additions of water. This means that once thesolutions are in the containers no further contact from the operator isrequired. When required the solutions in the containers are heated bythe 12 volt heater (22) whose operation is regulated by the temperatureprobe which feeds temperature data to the computer control. A cassette(34) containing the film to be processed is located in the compartment(33) provided for this purpose. A length of film is drawn out from thecassette and fed via the shute (37) and connected to the belt (38) onthe spiral (32). The lid (31) is then closed on that processing unit.The spiral is then rotated by appropriate drive means and the film isdrawn from the cassette (34) and wound onto the spiral. As has beenexplained the shute acts to assist this operation by bowing the film sothat it can be fed correctly between the lands which are formed on thespiral. When the film has been completely drawn out from the cassette(34) this is sensed and the drive to the spiral is declutched. The filmcan then be cut by operating the knife (40). If necessary a further filmcan then be loaded in a simpler manner to one of the other processingunits (30).

At this point in the operation the computer will by way of the display(49) inform the operator of its status and call for the operator toinput the type of film and the type of process required. The machine canbe arranged so that it is always ready to process film irrespective ofthe temperature of the chemicals in the containers (18, 19, and 20). Thecomputer control can be programmed to automatically adjust theprocessing time to take account of temperature of the chemicals andtheir state of exhaustion. However in normal operation the machineshould have been left on standby and the chemicals preheated to theoptimum temperature. When the operator has inputted the type of film andprocess required the delivery of chemicals from the containers (18, 19and 20) to the processing units (30) takes place. This occurs under theinfluence of gravity. The chemicals are fed by way of the valves (25 and26) to the chamber (35). A level detector is provided to sense the levelof liquid in the chamber and at an appropriate time causes the valve(25) to close so that no more liquid is fed to the processing unit. Whenthe liquid has reached the desired level the process treatment startswith the spiral (32) rotating. After a predetermined time determined bythe computer control the valve (15) is again opened and the pump (24)starts operating. This causes the chemical to be pumped back to theappropriate container (18, 19 or 20) following which the valve (25) isclosed and the valve (26) is operated to select an outlet (50) throughwhich any remaining chemicals can drain. Further chemicals can be fedinto the unit (30) in a similar manner to complete the developingprocess, each container has its own valve and pump station.

The unit can be provided with a heater to supply hot air to the filmheld on the spiral in the processing unit (30). This air can be forcedin by means of a fan heater (not shown) the air being fed into thechamber (35) by way of light traps behind an inlet (51). Air can exhaustvia a vent with light traps in an opposite wall. Alternatively the filmcan be taken out wet if desired.

To remove the processed film the lids (31) are unlocked and the spiralremoved and the film unwound from the spiral.

It should be noted that the pairs of units (30) can be arranged so thatone part may be operating one process at the same time as the other partis operating another different process. One such process may be stoppedwithout the other having to be interrupted.

It will be appreciated that after use the case lid can be closed andlatched and the whole unit taken to another location if necessary.Bottles containing used chemicals can be removed by inverting andunplugging them and new chemicals located therein.

The apparatus described above has a number of features which areconsidered to be significant inventive both singly and in combination.These include the following:

The provision of a self-contained photographic film processing unitwhich does not require a dark room for its operation. The unit can beoperated from a 12 volt supply such as a car battery.

The provision of such a processing unit in which the chemicals aresupplied ready mixed.

A portable processing unit having automatic processor control. The useof processor control allows the unit to adopt a low temperature start upprocess which may be necessary if film is required quickly before thedeveloping chemicals have reached an optimum temperature.

The unit can be used at low power and low voltage and the computer canbe designed to carry out a power sharing function to conserve power.

The unit can have two film processing stations running in parallel. Itis possible to stop one processing station and remove the film from thatstation while film is still being developed in the other station.

We claim:
 1. A portable film processing unit comprising:loading meansfor receiving a film cassette containing undeveloped film; at least oneprocessing chamber; at least one receptacle means for containingprocessing fluids; coupling means for coupling each receptacle means toeach processing chamber; valve means for selectively permitting flow ofprocessing fluids between each receptacle means and a respective one ofthe processing chambers; removal means for removing the film from itscassette and winding it onto a spiral type holder located in aprocessing chamber, the loading means, the removal means, and theprocessing chambers being housed in light-tight conditions; and pumpmeans to facilitate the flow of processing fluid from the processingchamber to respective receptacle means, the arrangement being such thatthe processing fluids can be dispensed from the receptacle means to aselected one of the processing chambers to perform a processingoperation on the film therein and, on completion of that processingoperation, the fluid can be returned under the influence of the pumpmeans to its respective receptacle means.
 2. A portable film processingunit according to claim 1, wherein a plurality of processing chambersare provided.
 3. A portable film processing unit according to claim 2,wherein four processing chambers are provided, the processing chambersbeing arranged in pairs to that one pair of chambers may operate aprocess which is different to that operated by the other pair.
 4. Aportable film processing unit according to claim 1, wherein heaters areprovided to heat the processing fluids in the receptacle means.
 5. aportable film processing unit according to claim 1, wherein cuttingmeans are provided to cut the film from its cassette after the film hasbeen wound onto the spiral type holder.
 6. A portable film processingunit according to claim 1, wherein drying means are provided to dry thefilm after processing.
 7. A portable film processing unit according toclaim 1, including electronic processing means for controlling at leastsome of the process parameters.
 8. A portable film processing unitaccording to claim 1, wherein said electronic processing means comprisesa microcomputer.